Electromagnetic rail brake



Oct. 24, 1950 A. ZUCKERMANN ELECTROMAGNETIC RAIL BRAKE Filed Aug. 8, 1947 IN VEN TOR.

N H M. UH E. K E U Z D N H M .H H

fl GENTS.

Patented Oct. 24, 1950 ELECTROMAGNETIC 'RAIL BRAKE Armand Zuckermann, Paris, France, assignor to Frems Jourdain-Monneret, Socit Anonyme,

Paris, France Application August 8, 1947, Serial No. 767,376

In France August 10, 1946 Claims. (01. 188-165) The present invention relates to improvements in electromagnetic track brakes for railway-cars.

These improvements particularly relate to the construction of the shoes of such brakes and in the arrangement of said brakes with relation to the railway-car.

The old conventional assembly of two brake heads rigidly cross-braced between the two parallel lines of rails gives rise to transverse air gaps resulting from differences in rail wear and variations in rail gauges. Further, due to the unevenness-of the treads of the rails, the rigid in the rail which sometimes interfere with the operation of D. C. automatic block signalling sys-,

tems.

.; In order to decrease the influence of longitudi nal air gaps, it has been already proposed to di-' vide each brake electromagnetic head into successive separate brake electromagnetic elements,

each of them comprising an individual core on which is wound an individual coil, each core also carrying side elements on which shoe elements are fixed. In these prior devices the opposite end brake elements are fixedly secured on a guiding frame .while the intermediate brake elements are freely'mounted on the frame, so that they may freely move in the vertical direction and freely pivotabout their edges of attach. However, the weight of each of the movable intermediate brake elements is sufficiently great, by reason of its yinclusion of a separate coil and'core, to induce rebouiidsQand the relative rigidity of .the terminal oropposite end brake elements resultsin longitudiri'al air gaps when said'latter brake elements contact a part of the rail projecting beyond the tread of said rail. i

With a view to overcoming all of these disad vantages, the'main object of the invention is to provide an electromagnetic track brake, the brake heads of which are of the kindcomprising successive separate brake elements, wherein all of the brake elements are freely movable vertically with respect to a common core and are also free to pivot in a vertical plane wherebythe brake elements contact the rail regardless of the irregularities'of its tread. Furthermore, each of the brake heads are fixed to the railway-car by 'meansjof a device which allows independent transverse displacement of each of the brake heads-and its pivotal movement about an axis parallel to the track, whereby the brake elements in each headcontact the associated rail regard less of the differences in rail wear and rail gauge.

Another object of the invention is to provide an electromagnetic track brake of the character described wherein the elementary brake elements are formed by shoe elements freely mounted on pins supported by the common core and common side frames, whereby no rebound is obtained due to the relative lightnesstof each of the elementary brake shoes...

A further objectltof this invention is to provide an electromagnetic track brake of thecharacter described; in which each of the shoe elements is formed ofa pair of magnetic shoes having 'a non-magnetic liner interposed therebetween, and in which the recesseson the opposite ends of each shoe element for receivingthe mounting pins are formed in the non-magnetic liner with the-ends of the magnetic shoes being merely cut-back to provide clearance whereby the difficult machining of the magnetic material is eliminated.

These, and other objects and advantages, will appear in the detailed description and in the accompanying drawings of an illustrative embodiment of the invention.

In the drawings: I

Figure v1 is a diagrammatic side elevation of one of the brake heads, with one of the side frames cut away to show the hinged shoe elements;

Figure 2 is a fragmentary vertical longitudinal section showing the hinged connection of the shoe elements in the brake head;

F igure 3 is .afragmentary vertical longitudinal section of a portion of a shoe element having a non-magnetic liner;

"Figure l is an .end elevation of the shoe element illustrated in Figure 3;

ures l gr thereof, a brake head constructed according to the invention is generally indicated by the letter A. Each brake head A includes. a pair of parallel extending vertical frames I, having the single coil 3 and core 3a fixed therebe-- tween. Extending between the lower portions of the side frames I are the fixed longitudinally spaced apart pins I9'and I9b. The opposite end pins being referred to by the numeral I912.

Brake shoe elements I8 and I8b are loosely received between the lower portions of the side frames I. The opposite end shoes I819 are formed on the end edges thereof facing the next adjacent intermediate shoe I8 with notches 2011 for loosely receiving the pins I9, and the intermediate shoe elements I 8 are formed with identical notches 20 formed in the opposite end edges 6 thereof. Each of the notches 20 includes a vertical flat surface 20a and quadri-cylindrical surfaces 201) at the top and bottom ends of the flat surface. radii of the quadri-cylindrical surfaces 222) are equal to that of the pins I9. The normal distance between the vertical surfaces 20a on the opposite ends of each of the shoe elements is substantially less than the distance between the surfaces of-the-pins t9 which the notches receive to thereby provide substantial clearance. The independent intermediate shoe elements I8 may then move vertically relative to the side frames I, and also pivot. in a vertical plane. Each of the opposite end shoe elements I8b, in addition to the notches 2nd formed in the end edges as noted above, is formed with an elongated slot 200, intermediate the length :thereof, which loosely receives the adjacent end pin I912. The end shoes I812 are thensupported from the side frames by the end pin I 917 and the next intermediate pin I 9. -By reason of the clearance between the end notches'and the slots and the respective pins, the end shoes [82) may also-move vertically and pivot in a vertical 'plane relative to the side frames:

Since each of .the shoe elements I8 and IBb is freely movable in the directions noted above, the shoe elements will closely follow the longitudinal configuration of the underlying railand the longitudinal 'air-gaps'between the shoes and'the rail will be substantially reduced} Whenthe common coil 3a is energized, the shoe elements I8 and I81) will be urgedagainst the underlying rail through which the magnetic field will be completed. Each shoe element is then submitted to a substantially horizontal force F in a direction opposed to the motion'of the railway car. By reason of the fiat portion 200. of each notch 20, the force will always be exerted normal to the point of contact of the pins IS with the flat portion. Therefore, there will be'no component of the braking force tending to rotate the shoe element and thus produce uneven pressure and wear on the braking surface of the shoe.

Furthermore, since onl the relatively light shoe elements I8 and I8b are movable, the single coil and core being fixed relative to the side frames, the rebounding of such shoe elements is substantially reduced. The mass of the 'shoe elements is not great, and therefore, the magnetic force urging the shoe elements ontothe rail will immediately return such small mass to the rail if any rebounding does occur. V

. In Figures 3 and 4, a shoe element is shown which consists of a pair of spaced outer portions 2| formed of a magnetic material, and an interposed central non-magnetic liner 22. The members 2| and 22 are secured together, and the outer portions are cut-back at the opposite ends as at 23. The notches 20 for receiving the pins I9 are then formed only in the end edges of the nonmagnetic liner 22. Since the recesses 23 of magnetic outer portions 2I of the shoe element do not engage the pins I9 there is no need to machine these recesses to close tolerances, and the portions 2| maybe cast. This construction makes it possible to use materials having the optimum magnetic and wearing characteristics, since there is no problem in machining the pin receiving notches.

In Figure 5 a preferred mounting of the opposite brake heads is illustrated. Since the distance between the rails may vary, and since the top surfaces of the rails may not always be transversely horizontal because of uneven wear, it is important that the opposite brake heads be permitted, to move transversely, independent of each other, and also that they be mounted for pivoting about horizontal axes parallel to the rails. Such mounting of the brake heads will reduce the transverse air gaps between the rails and the shoe elements. The preferred mounting includes a cross-member I0 supported at its opposite ends by the rods 4. The rods 4 are supported by spring members interposed between fixed members 5 of the railway-car truck and the top ends of the rods. The opposite brake heads A are dependingly carried from the cross-member Iii by the links 26, pivoted on pivot pins 21 on the cross-member, and the stirrups 29. The stirrups 29 are pivotally connected to the lower ends of the links 26 by the pins 28. Finally, the

arms of the stirrups 29 are'connected at 25 to the side frames I of each brake head. It is apparent that the side frames I of the opposite brake heads may both move transversely and also pivot around axes corresponding to the pins 2'! and 28. Thus the shoe elements I8 and I8!) are capable of moving vertically and pivoting in a vertical plane independent of each other, and the shoe elements in each brake head are, as a unit, capable of transverse movement and also rocking about axes parallel to the rails. These several motions provide a magnetic brake assembly in which the air gaps between the shoes and the rails are effectively reduced, thus increasing the braking force, reducing variations in the magnetic force which produce voltages in the rails interfering with the operation of D. C. block signalling systems, and also insuring even contact between the shoes and rails to provide symmetrical wearing of the parts.

In Figure 6, a suitable pivotal connection between the links 26 and the pivot pins 21 is shown- The link 26 has atubular member 38 fixed in one end thereof. A bushing 32 of plastic material is received by the member 30, and an inner tube 3| is disposed in'the plastic or resilient bushing porting cross-member, a longitudinally extend: ing brake head depending from each of the oppo-f site ends of said cross-member, each ofsaid brake heads being transversely movablelandpivoting} about a longitudinal horizontal axis whereby said brake heads may conform to variations in the track gauge and transverse inclinations in the tread of the underlying rails, each of said brake heads including a common magnetizing coil and core, a pair of side frames fixed to said core, and a plurality of longitudinally arranged independent shoe elements loosely carried between said side frames, said shoe elements each being movable up and down between said side frames and rockable in a plane parallel to said side frames whereby said shoe elements may conform to the longitudinal configuration of the underlying rails.

2. In an electromagnetic track brake for a railway car, a transversely extending cross-mem her, a brake head disposed at right angles to said cross-member at each of the opposite ends of the latter, link means supporting each of said brake-heads from said cross-member, said link means being pivoted at the opposite ends thereof and movable in a vertical transverse plane whereby each of said brake heads may move transversely and also rock about an axis parallel to the underlying rail independent of the other brake head, each of said brake heads including a pair of side frames, a common coil and core carried by said side frames, a plurality of longitudinally arranged independent shoe elements projecting beyond the bottom edges of said side frames, and means loosely mounting said shoe elements between said side frames adapted topermit up and down linear movement of said elements in a plane parallel to the plane of said side frames and rocking of said elements in said plane of up and down movement whereby said elements may conform substantially to the longitudinal configuration of the underlying rail.

3. In an electromagnetic track brake having a pair of longitudinally extending spaced apart brake heads for braking action on the pair of underlying rails, mounting means for each of said brake heads permitting independent transverse movement of said brake heads and pivoting of said brake heads about a longitudinal horizontal axis to thereby suppress transverse air gaps between the rails and the brake heads, each of said brake heads includin a frame, a single magnetizing coil and core, a plurality of indepedent shoe elements for braking contact with the underlying rail, and means mounting said elements on said frame adapted to permit up and down movement of each element relative to said frame and independent rocking of said elements in a substantially vertical longitudinal plane.

4. In an electromagnetic track brake, the combination according to claim 3, wherein each of the intermediate shoe elements is formed with vertically elongated recesses in the opposite end edges thereof, each of the opposite end shoe elements is formed with a vertically elongated recess in the end edge thereof confronting the adjacent intermediate shoe element and with a vertically elongated opening intermediate the length of said end shoe element, and wherein the last mentioned mounting means includes a plurality of longitudinally spaced apart cross-pins carried by said side frames and loosely received in said end edge recesses and in said openings, substantial longitudinal clearance being provided between said pins and said recesses and openings to thereby permit up and down movement of said elements and rocking of the latter in a substantially vertical longitudinal plane.

5. In an electromagnetic track brake, the combination according to claim 3, wherein the first mentioned mounting means includes a resiliently supported cross-member, a link for each of said brake heads pivoted at one end to said crossmember and rocking in a transverse plane, a stirrup pivotally mounted at its center on the opposite end of each of said links for rocking in a transverse plane, each of said stirrups being secured at the ends thereof to one of said brake heads whereby each of said brake heads may move at right angles to the longitudinal axis and also rock in a transverse plane to thereby conform to the transverse contours of the underlying rails.

ARMAND ZUCKERMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 545,554 Thomson Sept. 3, 1895 663,519 Sohiemann Dec. 11, 1900 2,054,716 Stedefeld et a1. SeptQlB, 1936 2,207,295 Latshaw July 9, 1940 FOREIGN PATENTS Number Country Date 678,156 Germany July 10, 1939 820,150 France July 26, 1937 823,411 France Oct. 18, 1937 827,409 France Jan. 24, 1938 

